Investigators looking into the murder of WPc Yvonne Fletcher are closer than they have "ever been" to achieving justice for her family, one of her former colleagues said today.
John Murray, who witnessed the 1984 shooting outside the Libyan Embassy in London, said he was confident that one of the key suspects would soon be arrested.
And he said a member of Libya's new government had assured him that Matouk Mohammed Matouk would stand trial, if he is caught.
The former Pc was standing just yards from WPc Fletcher when she was gunned down.
At the time he vowed to track her killers. He has now travelled to Libya as part of his attempt to seek justice.
"Twenty-seven years is a very long time but my trip here to Libya has brought me closer than ever to a final conclusion," he told the BBC.
"It's the closest we've ever been. It's strange, here in Tripoli, the support from the Libyan people, the support from the NTC (National Transitional Council), they all know about Yvonne Fletcher, they all know what happened. They all know the people who were responsible and I'm really overwhelmed by their support."
Matouk is the only suspect in the shooting believed still to be alive.
"We believe he's still in Tripoli," Mr Murray said.
"The NTC are actively looking for him as well but I've got no doubt that very, very soon he will be detained."
And he told the broadcaster that Abdul Hafiz Ghoga, the NTC's vice-chairman, had offered him "tremendous hope", saying that if the man is detained, he will be prosecuted and could potentially be extradited to Britain.
WPc Fletcher was shot while policing a protest outside the Libyan embassy.
As she lay in an ambulance before she died, Mr Murray "cradled her head", promising his colleague he would find her attackers.
"When she was still conscious, I said to her 'Don't worry, Yvonne, I will find the people who did this, don't worry, we will get them'," he said.
Last month rebel officials in Tripoli said one suspect, Abdulqadir al-Baghdadi, an official in the embassy at the time, had been shot in the head.
Junior diplomat Abdulmagid Salah Ameri, who was suspected of firing the fatal shots, was never traced after he was deported along with other embassy officials after an 11-day stand-off and is thought to have died.